Mankind has been devising methods and creating devices to remove liquids from a vessel's bilge since the building of the first boat. During the age of exploration, the reliable bucket was replaced with a simple tube with a piston sealed with leather. The piston was raised and lowered causing the bilge liquid to be expelled. In modern times, electrical/mechanical bilge pumps have been utilized.
Today, automatic bilge pumps come in three basic forms: the centrifugal impeller, rubber lobe impeller and a diaphragm pump. All these designs share a common shortcoming. After the pump has cycled off or turned off, a base liquid level remains in the vessel's bilge. The present invention solves the problem of removing the base bilge liquid that remains after the primary bilge pumps have turned off.
The vertical shaft impeller, submersible pump disclosed in U.S. Pat. No. 4,013,383 to Clinton Rule is one of the most popular, durable and efficient bilge pumps available on the market today. However, despite its great capacity, it leaves a large amount of residual bilge water after it has completed a cycle. Generally, larger bilge pumps mean greater water flow, but also mean higher residual bilge liquid or water levels. Although smaller sized pumps provide lower residual water levels, smaller pumps would not be as helpful in keeping vessels afloat in the event of an emergency. Moreover, the centrifugal, vertical shaft impeller pumps need to reside in the bilge water, which over time, foul the pump. There is a need for a bilge liquid removal system in which the pump does not come in direct contact with the bilge liquid.
The lobe impeller pumps tend to pull the base water levels lower depending upon the installation. Lobe impeller pumps are typically mounted above the bilge because these pumps are generally not water proof. Similarly, the smaller the pump size and suction hose, the greater their ability to draw the water levels lower. Generally, the lobe impeller pumps require a lot of electrical power, produce much noise and have been known to overheat when run dry, causing the rubber lobe impellers to melt to the housing, and finally, seizing the pump.
The diaphragm pump works like the heart, in that it flexes causing valves to open and close. These pumps are able to draw a residual bilge water level to a lower level than the centrifugal and lobe impeller pumps because this type of pump can be left to run dry and has the ability to pump air. However, diaphragm pumps are typically very noisy, draw a lot of power, and are susceptible to debris being caught in one of the valves, disabling the pump.
The present invention solves the problem of residual bilge liquid or water by providing a bilge liquid removal system and method.
The prior art includes pneumatic disposal systems. For example, U.S. Pat. No. 3,780,757 to Jordan discloses a system for the servicing of toilet waste holding tanks. The system disclosed in '757 to Jordan selectively applies a vacuum or air pressure to a waste holding tank and a flushing fluid holding tank in order to draw the waste from the target waste holding tank. The intake hose for the removal of waste from the target holding tank includes a check valve.
U.S. Pat. No. 4,623,452 to Peterson discloses a pneumatic dockside system for the removal of bilge water and waste oil. The system disclosed in '452 to Peterson includes a dockside collection tank having the input pipe extending to the bottom of the vacuum tank. The input pipe is perforated to prevent syphoning from the vacuum tank back through the evacuator pipe.
U.S. Pat. No. 3,883,269 to Wolff discloses a pneumatic liquid transfer system for marine applications, and particularly with regard to storage and transfer of cargo aboard barges.
U.S. Pat. No. 1,813,255 to Petre discloses a pneumatic means for removal of bilge water from motor boats by utilizing an auxiliary chamber with a float for the collection of bilge water. The engine of the boat is used to create the vacuum in the chamber. When the float in the auxiliary chamber reaches a particular point, a valve opens permitting air to enter the chamber, destroying the partial vacuum. A one-way valve on the intake pipe closes and a similar valve on the exit pipe opens. This causes the accumulated bilge water to exit via an outlet pipe.